Recently, an enlargement of a market of flat-screen devices typified by a liquid display augments a demand for the transparent conductive film. The transparent conductive film is employed, for example, for an electrode. Or, it is employed for a resistive touch panel. Or, it is employed for an electromagnetic wave shielding film. It is employed for various fields besides them. The transparent conductive film of this type, as a rule, is configured of metal oxide such as Indium thin oxide (ITO). And, the transparent conductive film such as ITO is manufactured with the methods such as sputtering. Thus, the film-forming with these methods necessitates a high temperature. For this, the use of a resin substrate having a poor heat-resistance is greatly restricted. In addition, the film-forming requires a vacuum environment. For this, a gigantic film-forming device is necessitated as the substrate become big. Thus, the film-forming becomes costly. Further, In is hard to obtain because it is a rare metal. Thus, ITO becomes costly from this viewpoint as well.
The alternative technology, which replaces ITO, has been proposed from such a background. In particular, the technology has been proposed of forming the carbon nanotube film with the coating method. Additionally, the transparent conductive film using the carbon nanotube is highly evaluated.
By the way, it is said that the single-walled carbon nanotube, out of the carbon nanotubes, is highest in conductivity. As it is, it is hard to disperse the single-walled carbon nanotube into a solvent. Thus, it is not easy to constitute the single-walled carbon nanotube conductive film with the coating technique. Thereupon, the technique employing a dispersing agent has been proposed. For example, it is proposed to employ sodium dodecyl sulfate (Non-patent literature 1). Further, it has been proposed to employ sodium dodecylbenzene sulfonate (Non-patent literature 1). Further, it has been proposed to employ octylphenol polyethylene glycol ether (Non-patent literature 1). Further, it has been proposed to employ sodium cholate (Non-patent literature 2). Further, it has been proposed to employ polyvinylpyrrolidone (Non-patent literature 3).